| Popis: |
C LINICAL experiences wi th echoenc epha log raphy have shown this procedure to be a va luab l e a id in the diagnosis of i n t r ac ran i a l mass lesions. 1-3,6 However , the usefulness of the p rocedure depends on es tab l i sh ing techniques for accu ra te loca l iza t ion of cer ta in mid l ine s t ructures of the brain. U l t r a son ic ref lect ions can be o b t a i n e d f rom a n u m b e r of s t ruc tu res inc luding the p inea l gland, 4 the s e p t u m pellucidum, 5 and the long i tud ina l fissure. 1 A recomm e n d e d si te for p l a c e m e n t of the probe, 4 and the si te mos t f r equen t ly used b y us to ob ta in these reflections, is a p o i n t above and an te r ior to the ear. W e have also used pos te r io r sites for eva lua t ion of o the r sup ra t en to r i a l midl inc s t ruc tures . A l t h o u g h sa t i s f ac to ry for ob ta in ing reflect ions f rom the midl ine , these areas a re also f requen t si tes of occurrence of subgalea l h e m a t o m a s af te r crania l t r auma . On rou t ine echoencepha log raphy the distances f rom the scalp to the midl ine reflection are c o m p a r e d to a theore t i ca l mid l ine es tabl ished ha l fway be tween the si tes of the probes on the scalp. T h e use of such a m e t h o d in the presence of an ex t rac ran ia l mass, such as a subgalea l h e m a t o m a , can give fac t i t ious evidence of a shif t in mid l ine s t ruc tu res a w a y f rom the side of the lesion. Our exper ience wi th th is p rob l em as well as a m e t h o d for o b v i a t i n g such an error is repor ted . |
